For most of us, Thanksgiving will be a time to chow down and experience deep calorie regret. Some of us may even do a guilt-fueled workout on Friday to work off the extra food.

Not Robert Durbin. The 64-year-old Louisville, Ky., married father of five doesn't need to talk himself into working out. He already does it seven days a week, for at least four hours a day. And he doesn't overeat. Not anymore.

Durbin wasn't always so disciplined. Seven years ago, he was so overweight that he felt his health was going downhill fast.

He was forced to wear braces, and needed a cane or a walker to get around.

With grandchildren on the way, Durbin decided to make a change. He joined a local gym and started working out on machines that didn't require him to stand. Within eight months, he had lost 60 pounds.

He's now dropped more than 70 pounds, lost 18 inches off his waist and weighs 145 pounds, but it's his increasingly ripped physique that's making him an Internet star.

About two years ago, Durbin discovered BarStarzz, an international workout team that uses creative calisthenics to achieve lean, muscled physiques. He saw their videos on YouTube and started working out to them on his own, posting photos and video of his progress on his Instagram account using the handle rockhardpapaw.

Courtesy Robin Durbin

BarStarzz noticed and interviewed him. The video of Durbin, who is flexing rock-hard, defined muscles while doing challenging one-armed push-ups, chin-ups, pull-ups and flagpole holds - in which one grasps a vertical object with both hands and pulls the body until it's horizontal and parallel to the ground - has been viewed more than 769,000 times since it was posted in October.

"I have no fear of getting older, I have a fear of getting lazy," wrote one viewer. "People retire and get lazy, which only helps to makes things get (worse) as we age. We always tell kids to exercise and go out and play, but older people should too. This man is proof that taking care of ourselves is key to having a happy older life. "

"That was the hardest part for me," he said. "I was a two plate person every meal, and right now I'm basically … well, I eat real clean."

He eats five or six small meals a day, and has eliminated fried foods from his diet.

And then there's the training, which he describes as rigorous.

Every morning right after he wakes up, he does about a mile on his elliptical ski glider, followed by 1,200 to 1,800 repetitions of abdominal exercises.

Then it's off to the gym, where he spends three hours doing CrossFit, weight training and skills training.

At night, he repeats his ski glider workout and abdominal exercises before he goes to bed. And he visits the gym several evenings per week for kettlebell, yoga and kickboxing classes.

Durbin says he feels better than he did when he graduated from high school. Back then, he drank and smoked. After a cancer scare, he quit his three-pack-a-day cigarette habit in 2004, and he hasn't touched a drop of alcohol in 20 years.